Odpowiedzi

2010-03-22T20:11:03+01:00
P = W/t |*t
P*t = W|:P
t = W/P - wzór z którego będziemy korzystać ;)

m = 25 kg
h = s = 48m
P = 300 W
g = 10 N/kg

W = F*s
F = m*g
F = 25*10
F = 250 N [F] = [kg* N/kg] = [N]

W = 250* 48
W = 12 000 J [W] = [N*m] = [J]

t = W/P
t = 12000/300
t = 40s [t] = [J/W] = [J / J*s] = [s]